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MySQL中多表删除方法

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Release: 2016-06-07 15:09:25
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欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入 如果您是才接触MySQL数据库的新人,那么MySQL中多表删除是您一定需要掌握的,下面就将为详细介绍MySQL中多表删除的方法,供您参考,希望对你学习掌握MySQL中多表删除能有所帮助。 1、从MySQL数据表t1

欢迎进入Linux社区论坛,与200万技术人员互动交流 >>进入

  如果您是才接触MySQL数据库的新人,那么MySQL中多表删除是您一定需要掌握的,下面就将为详细介绍MySQL中多表删除的方法,供您参考,希望对你学习掌握MySQL中多表删除能有所帮助。

  1、从MySQL数据表t1中把那些id值在数据表t2里有匹配的记录全删除掉

  DELETE t1 FROM t1,t2 WHERE t1.id=t2.id 或DELETE FROM t1 USING t1,t2 WHERE t1.id=t2.id

  2、从MySQL数据表t1里在数据表t2里没有匹配的记录查找出来并删除掉

  DELETE t1 FROM t1 LEFT JOIN T2 ON t1.id=t2.id WHERE t2.id IS NULL 或

  DELETE FROM t1,USING t1 LEFT JOIN T2 ON t1.id=t2.id WHERE t2.id IS NULL

  3、从两个表中找出相同记录的数据并把两个表中的数据都删除掉

  DELETE t1,t2 from t1 LEFT JOIN t2 ON t1.id=t2.id WHERE t1.id=25

  注意此处的delete t1,t2 from 中的t1,t2不能是别名

  如:delete t1,t2 from table_name as t1 left join table2_name as t2 on t1.id=t2.id where table_name.id=25 在数据里面执行是错误的(MySQL 版本不小于5.0在5.0中是可以的)

  上述语句改写成

  delete table_name,table2_name from table_name as t1 left join table2_name as t2 on t1.id=t2.id where table_name.id=25 在数据里面执行是错误的(MySQL 版本小于5.0在5.0中是可以的)

  以上就是MySQL中多表删除的方法介绍。

MySQL中多表删除方法

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